WA residents are sweltering through a severe heatwave, with temperatures soaring to the high 40s in northern parts of the state. 

The Pilbara region hovered around 30C on Friday night, with the Bureau of Meteorology warning temperatures could rise to 48C in coming days.

A high fire danger rating has been issued for large parts of WA on Saturday, with residents told to be prepared.

“We have a heat trough stalling over that area,” bureau meteorologist Miriam Bradbury told the ABC.

“It’s a weather system which isn’t going anywhere fast and the heat is really just circulating over the area, stagnating. We haven’t had a strong system to clear it all.

“That heat over the past few days has started to slide south-eastwards towards SA, Victoria, Tasmania and NSW.”

That system will cause temperatures to rise in NSW and parts of southern Queensland on Saturday, with forecasts in the low to mid 30s.

“We are going to see some relief about those southern and central NSW coastal areas tomorrow,” Ms Bradbury said.

“The further inland we move, the more persistent that heat is going to be.

“Northern NSW, southern Queensland and WA are just going to hang on to that heat with a fresh burst moving across the southeastern states from the middle of the week.”

Meanwhile in northern Queensland, monsoon warnings remain in place with six-hourly rainfall totals of up to 130 millimetres forecast for the Gulf Country and Cape York Peninsula.

The heavy rain could lead to further flash and riverine flooding, with minor to moderate flood warnings in place for western Queensland and the Gulf Country.

Further south, there is a brief heatwave reprieve in Victoria after Melbourne recorded its hottest day since January 2020.

The city reached a top of 40.5C at 3.47pm on Friday before rapidly dropping to 27.6C by 4pm.

Temperatures will not exceed 23C in Melbourne on Saturday but another heatwave is forecast for the state late next week.